Fixation Process For Nesting Stents

Abstract

A stent graft device that requires an anchor setting procedure to prevent migration of the stent, such as an endovascular anchor stent device used for treatment of an abdominal aortic aneurism, can be anchored to a blood vessel by electrosurgically disrupting portions of the blood vessel in situ to affix struts of the stent graft device to the vessel wall, replacing barbs which have been used in such devices. The stent graft device can have a wire frame and struts or a cannula stent frame body with struts cut from the cannula. The struts can be provided with openings which are filled with extracellular matrix material, which encourages and speeds ingrowth of the struts in the vessel wall.

1 . A system for securing an endovascular prosthesis in a body cavity, comprising:
 a prosthesis introducer;   at least one expandable bio-compatible frame body disposed on the introducer, the frame body being contractible into a first shape with a smaller diameter for introduction to a vascular site and being radially expandable into a second shape having a larger diameter;   the frame body comprising at least partially electrically conductive struts in contact with and for attachment to an inner wall of the body cavity; and   an insulated electrical conductor, electrically contacting at least one strut of the at least partially electrically conductive struts in contact with the inner wall of the body cavity, the electrical conductor being connectable to radio frequency electrical power, for providing electrical energy for a sufficient time at a sufficient power to affix the strut to the inner wall of the body cavity.   
     
     
         2 . The system according to  claim 1 , wherein the expandable frame body is a tubular stent comprising metal, and wherein at least one strut of the struts has at least one opening in the strut. 
     
     
         3 . The system according to  claim 2 , wherein extracellular matrix material is disposed in the at least one opening. 
     
     
         4 . The system according to  claim 2 , wherein the at least one opening comprises a bore having a depth extending all the way through the strut, and wherein the extracellular matrix material extends through the depth. 
     
     
         5 . The system according to  claim 1 , wherein the at least one strut has a partial coating of an electrical insulator. 
     
     
         6 . The system according to  claim 5 , wherein the partial coating of an electrical insulator comprises a parylene selected from
 parylenes having a formula (—CH 2 —C 6 H 3 Cl—CH 2 —) n ,   parylenes having a formula (—CH 2 —C 6 H 4 —CH 2 —) n ,   parylenes having a formula (—CF 2 —C 6 H 4 —CF 2 —) n , and   mixtures thereof.   
     
     
         7 . A method for placing a prosthesis to repair a defect in a body cavity, comprising the steps of:
 providing a catheter with a preloaded prosthesis comprising at least one expandable tubular bio-compatible at least partially electrically conductive frame body,
 the expandable tubular bio-compatible at least partially electrically conductive frame body being contractible into a first shape with a smaller diameter for introduction into a body cavity and being radially expandable into a second shape having a larger diameter, 
 the expandable tubular bio-compatible at least partially electrically conductive frame body having at least partially electrically conductive struts for attachment to an inner wall of the body cavity, and having an insulated electrical conductor, electrically contacting at least one of the at least partially electrically conductive struts for attachment to the body cavity, the insulated electrical conductor being connectable to radio frequency electrical power, for providing electrical energy for a sufficient time at a sufficient power to affix the at least one of the at least partially electrically conductive struts to the inner wall of the body cavity; 
   introducing the catheter and the preloaded prosthesis into the body cavity and advancing to a treatment site;   releasing the prosthesis from the catheter and expanding the prosthesis so that at least one at least partially electrically conductive strut contacting the electrical conductor is in contact with the body cavity; and   connecting the electrical conductor to radio frequency electrical power for a sufficient time at a sufficient power to affix the at least one at least partially electrically conductive strut to the inner wall of the body cavity.   
     
     
         8 . The method according to  claim 7 , wherein the electrical conductor is subsequently removed. 
     
     
         9 . The method according to  claim 7 , wherein the expandable tubular bio-compatible at least partially electrically conductive frame body is a stent, and wherein the at least partially electrically conductive struts have at least one opening therein for the receipt of extracellular matrix material. 
     
     
         10 . The method according to  claim 9 , wherein the at least one opening comprises a bore having a depth extending all the way through the at least partially electrically conductive struts, and wherein the extracellular matrix material extends through the depth. 
     
     
         11 . The method according to  claim 7 , wherein the expandable tubular bio-compatible at least partially electrically conductive frame body and struts are formed from metal wire. 
     
     
         12 . The method according to  claim 7 , wherein the sufficient time and the sufficient power accomplish a preliminary attachment of the strut to the inner wall of the body cavity, the preliminary attachment being of such strength that the preliminary attachment can be broken without harming the wall of the body cavity to which the prosthesis is attached. 
     
     
         13 . The method according to  claim 7 , wherein
 the endovascular prosthesis is preliminarily deployed in a preliminary placement;   an initial sufficient time and an initial sufficient power accomplish a preliminary attachment of a strut to the inner wall of the body cavity;   the preliminary placement of endovascular prosthesis is observed by a physician after the preliminary attachment of the bio-compatible material to the inner wall of the body cavity;   the preliminary attachment is broken;   the endovascular prosthesis is deployed in a new placement;   the new placement of endovascular prosthesis is observed by a physician; and   a second sufficient time and a second sufficient power accomplish a secondary attachment of the strut to the inner wall of the body cavity.   
     
     
         14 . The method according to  claim 13 , wherein the body cavity is an aorta, the initial sufficient time is from about 3 to about 4 seconds, the initial sufficient power is from about 70 to about 80 watts, the second sufficient time is from about 3 to about 4 seconds, and the second sufficient power is from about 95 to about 150 watts. 
     
     
         15 . A fixation process for implanting an at least partially electrically conductive endovascular prosthesis within a body cavity, comprising the steps of:
 contacting an electrical conductor that is supplied with radio frequency electrical power to at least a portion of the at least partially electrically conductive endovascular prosthesis;   positioning the at least partially electrically conductive endovascular prosthesis within the body cavity in contact with a wall of the body cavity; and   activating the radio frequency electrical power for sufficient time at sufficient power to affix at least a portion of the at least partially electrically conductive endovascular prosthesis to the wall of the body cavity.   
     
     
         16 . The fixation process according to  claim 15 , wherein the sufficient time and sufficient power accomplish a preliminary attachment of the at least partially electrically conductive endovascular prosthesis to the inner wall of the body cavity, the preliminary attachment being of such strength that the preliminary attachment can be broken without harming the wall of the body cavity in need of reinforcement to which the at least partially electrically conductive endovascular prosthesis is attached. 
     
     
         17 . The fixation process according to  claim 15 , wherein
 the endovascular prosthesis is preliminarily deployed in a preliminary placement;   an initial sufficient time and an initial sufficient power accomplish a preliminary attachment of the at least partially electrically conductive endovascular prosthesis to the inner wall of the body cavity;   the preliminary placement of at least partially electrically conductive endovascular prosthesis is observed by a physician after the preliminary attachment to the inner wall of the body cavity;   the preliminary attachment is broken;   the endovascular prosthesis is deployed in a new placement;   the new placement of the endovascular prosthesis is observed by a physician; and   a second sufficient time and a second sufficient power accomplish a secondary attachment of the endovascular prosthesis to the inner wall of the body cavity.   
     
     
         18 . The fixation process according to  claim 17 , wherein the endovascular prosthesis comprises a tubular bio-compatible metallic frame body. 
     
     
         19 . The fixation process according to  claim 15 , wherein the body cavity is an aorta, wherein the initial sufficient time is from about 3 to about 4 seconds, the initial sufficient power is from about 70 to about 80 watts, the second sufficient time is from about 3 to about 4 seconds, and the second sufficient power is from about 95 to about 150 watts. 
     
     
         20 . An expandable metal frame stent for securing an endovascular prosthesis in a body cavity, the metal frame stent being contractible into a first shape with a smaller diameter for introduction to a vascular site and being radially expandable into a second shape having a larger diameter;
 the frame stent comprising struts for attachment to an inner wall of the body cavity;   at least one strut of the struts having at least one opening in the strut; and   extracellular matrix material being disposed in the at least one opening; and   wherein the struts have a partial coating of an electrical insulator; and   where in the partial coating of an electrical insulator comprises a parylene selected from   parylenes having a formula (—CH 2 —C 6 H 3 Cl—CH 2 —) n ,   parylenes having a formula (—CH 2 —C 6 H 4 —CH 2 —) n ,   parylenes having a formula (—CF 2 —C 6 H 4 —CF 2 —) n , and   mixtures thereof.